The compound 1-methyl-5-nitroimidazole-2-yl methylcarbamate, known as ronidazole, has long been known (U.S. Pat. No. 3,646,027) to be a potent agent to decrease the activity of protozoa and bacteria. It, however, suffers from severe handicaps to any practical use for this purpose because of high drug residual levels and strong mutagenicity, which render it impractical for animals to be used for human consumption. There is, thus, a strong need for a drug of like potency which would not have these deleterious side effects.